Imidoether and amidine derivatives of substituted fatty amides

ABSTRACT

An imidoether having the formula   IS PREPARED BY REACTING   WITH METHANOL IN THE PRESENCE OF A SODIUM METHOXIDE CATALYST, AND AN AMIDINE SALT HAVING THE FORMULA   IS PREPARED BY REACTING THE IMIDOETHER WITH AMMONIUM CHLORIDE OR AMMONIUM BROMIDE IN THE PRESENCE OF METHANOL. The imidoethers are used to prepare the amidine salts, which in turn are useful as stabilizers for polyesters.

United States Patent [1 1 Scanlon et al.

[ 1 June 26, 1973 IMIDOETIIER AND AMIDINE DERIVATIVES OF SUBSTITUTEDFATTY AMIDES [75] Inventors: Patricia M. Scanlon, Arlington,

Mass.; Elwyn R. Young, Nashua,

[73] Assignee: W. R. Grace & Co., New York, NY.

[22] Filed: Mar. 10, 1971 [21] Appl. No.: 128,613

Related US. Application Data [62] Division of Ser. No. 830,091, June 3,1969, Pat. No.

OTHER PUBLICATIONS Roger et al., The Chem. of Imidates" (1961) Chem.Rev. Vol. 61, pp. 179, 181, 193 (1961).

Primary Examiner-Lewis Gotts Assistant Examiner-G. Hollrah Attorney-W.R. Grace [57] ABSTRACT An imidoether having the formula is prepared byreacting with methanol in the presence of a sodium methoxide catalyst,and an amidine salt having the formula is prepared by reacting theimidoether with ammonium chloride or ammonium bromide in the presence ofmethanol. The imidoethers are used to prepare the amidine salts, whichin turn are useful as stabilizers for polyesters.

2 Claims, No Drawings IMIDOETIIER AND AMIDINE DERIVATIVES F SUBSTITUTEDFATTY AMIDES CROSS REFERENCE TO RELATED APPLICATION This is a divisionalof Application Ser. No. 830,09l, filed 3 June 1969, and now U.S. Pat.No. 3,64l,l03.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION In summary, thisinvention is directed to an amidine salt having a formula selected fromthe group consisting of wherein X is an ion selected from the groupconsisting of chloride and bromide.

DESCRIPTION OF PREFERRED EMBODIMENTS In a preferred embodiment thisinvention is directed to a process for preparing an amidine salt havinga formula selected from the group consisting of wherein Xis an ionselected from the group consisting of chloride and bromide, comprising:

' a. forming a product mixture consisting essentially of the amidinesalt and methanol by contacting and reacting at about -40C.(preferablyabout -30C.) an imidoether having a formula selected from thegroup consisting of C Ha- CH CN and OCIIs CH CN with an ammonium salthaving the formula NH X, wherein X is an ion selected from the groupconsisting of chloride and bromide in the presence of methanol, the moleratio of the imidoether to the methanol being about 1:20-60 (preferablyabout 1:20-40); the mole ratio of the imidoether to the ammonium saltbeing about 1 1-2, and the contact time being about 20 hours (preferablyabout 2-l5hours);

b. separating the thus formed amidine salt from the methanol (e.g., byfiltration, centrifugation, or decantation); and

c. recovering the separated amidine salt.

In another preferred embodiment this invention is directed to a processfor preparing an amidine salt having the formula INC-CHzN=(CIIz-C=NH)2-2HX wherein X is an ion selected from the groupconsisting of chloride and bromide, comprising:

a. forming a product mixture consisting essentially of the amidine saltand methanol by contacting and reacting at about 20-35C. (preferablyabout 25-30C.) an imidoether having the formula with an ammonium salthaving the formula NH X, wherein X is an ion selected from the groupconsisting of chloride and bromide in the presence of methanol, the moleratio of the imidoether to the methanol being about 1:15-30 (preferablyabout 1210-25), the mole ratio of the imidoether to the ammonium saltbeing about 1:1-3 preferably about 111-2), and the contact time beingabout 1-24 hours (preferably about 2-8 hours);

b. separating the amidine salt from the methanol (e.g., by filtartion,centrifugation, or decantation); and

c. recovering the separated amidine salt.

In another preferred embodiment this invention is directed to a processfor preparing an imidoether having a formula selected from the groupconsisting of (win and

NEICIIgCNJa,

in the presence of a catalytic quantity of an alkali metal akloxide, themole ratio of the nitrile to the methanol being about 1:15-30(preferably about 1:10-40); and

b. separating the imidoether from the methanol and alkali metal alkoxidee. g., by filtration, centrifugation, or decantation the imidoetherbeing only slightly soluble in methanol and the alkali metal alkoxidebeing very substantially soluble in methanol). If desired, a quantity ofmethanol can be evaporated from the methanol-imidoether-alkali metalalkoxide mixture, thereby to decrease the volume of methanol present todissolve the imidoether and thereby to increase the recovery of theimidoether.

GENERAL DESCRIPTION OF THE INVENTION The amidine salts of this inventionare obtained from a-amino nitriles by allowing the a-amino nitriles toreact with methanol in the presence of a metal alkoxide to form animidoether. The intermediate imidoether is then allowed to react with anammonium salt in methanol to form the desired amidine salt.

The amidine salts of this invention are useful as stabilizers forpolyesters, and the imidoethers of this invention are useful in thepreparation of such amidine salts.

In the polyester art and polyester preparation art the term stabilizerhas come to mean an additive which is effective in retarding orpreventing polymerization of premixed polyester compositions prior tomolding but which is substantially without effect upon polymerizationunder the conditions prevailing during molding where a catalyzedpolyester composition is subjected to elevated temperatures suchtemperatures being well in excess of normal room temperatures of about20-30C. An inhibitor differs from a stabilizer primarily in that theinhibitor retards or prevents polymerization at normal room temperaturesand at the elevated temperatures generally used in molding polyesters.In other words, stabilizers are effective in preventing or retarding thepolymerization of premixed polyester compositions where suchcompositions are stored at about normal room temperature withoutsubstantially retarding the'catlyzed polymerization of such compositionsunder molding conditions (i.e., under elevated temperatures).

. We have found that the imidoethers and amidine salts ofthisinvention-can be prepared from nitriles by a sequence of reactionsrepresented by the following equations (where R is CH (CH,) C H,,, or

5 CH and X is Cl'or Br): a

lCHzONa IO Where usingnitrilotriacetonitrile as the nitrile the sequenceof reactions is represented by the following equations (where X is Cl'orBr):

(N-cyanomethyl-nitrilodi-acetamidine dihydrohalide) Our invention isfurther illustrated by the following specific but nonlimiting examples.

EXAMPLE I (Preparation of N-Acetyliminodiacetonitrile) Acetyl chloride(78.5 g; 1.0 mole) was added to a slurry of iminodiacetonitrile (190.2g; 2.0 moles) in 400ml. of reagent grade acetone in a 1 liter flaskfitted with a stirrer, thermometer, and reflux condesnder. Thetemperature was allowed to rise spontaneously during the addition of theacetyl chloride (maximum temperature 62) and the reaction mixture wasrefluxed for 2 hours. After cooling, the product was collected byfiltration, washed with acetone and air-dried. The filtrate was allowedto evaporate at room temperature leaving a gummy-like residue (147 g) ofcrude N- acetyliminodiacetonitrile. (This material is a low meltingsolid, mp. about 36-37C.). The crude product was used in Example ll,infra, for the preparation of an imidoether and an amidine salt.

EXAMPLE II (Preparion ofN-acetyl-N-carboxamidinemethylglycinonitrile-hydrochloride) CrudeN-acetyliminodiacetonitrile (79 g, 0.57 mole) was added to a solution ofsodium methoxide (2.7 g, 0.057 mole) in 300 ml. anhydrous methanol in a1 liter flask fitted with a stirrer, thermometer, and drying tube. Theclear reaction mixture was stirred at room temperature for 2 hours.After standing overnight, the solid present was collected by filtrationand air-dried. More solid was obtained by evaporation of the filtrate. Atotal of 54.5 g (corresponding to a yield of 57 percent of theory) ofcrude imidoether was obtained. This material was identified by itsinfrared spectrum as N- acetyl-N-(Z methyl acetimidate)-glycinonitrile.

The crude imidoether (20.6 g) was placed in a 250 ml. flask fitted witha stirrer, thermometer, and drying tube. Anhydrous methanol, 75 ml., wasadded and most of the solid dissolved. Ammonium chloride (7.0 g, 0.13mole) wasadded on one portion. The reaction mixture was stirred for 2.5hours, during which time a precipitate formed. After standing overnight,a pale yellow NHz CHzCN by its infrared spectrum and comparison of thisspectrum with those of the other amidin-e salts described, weighed 15.7g. (corresponding to a yield of 68 percent of theory).

EXAMPLE Ill (Preparation ofN-lauroyl-N-carboxamidinemethylglycinonitrile hydrochloride) In a 1liter flask fitted with a stirrer, thermometer, and drying tube wasplaced 109 g (0.39 mole) of N- lauroyl-iminodiacetonitrile, 2 g (0.04mole) of sodium methoxide, and 500 ml. (ca. 12 moles) of anhydrousmethanol. After stirring for approximately minutes, all the soliddissolved. The clear, orange-yellow solution was stirred an additional4.5 hours at room temperature. After standing overnight, a pale yellowsolid was present. The solid was collected (by filtration) washed withether and air-dried. Additional solid was recovered from the filtrate byevaporation. A total of 114 g (corresponding to a yield of 94 percent oftheory) of crude imidoether was obtained. This imidoether was identifiedas N-lauroyl-N-(2-m'ethyl acetimidate)- glycinonitrile, by infrared andthe determination of its equivalent weight. Titration of this samplewith a'lcoholic l-lCl gave an equivalent weight of 322. The crudeimidoether melted at ca. 8893C. and softened at 87C.

Ammonium chloride (2.7 g; 0.05 mole) was added with stirring to a slurryof 15.5 g of the crude imidoether in 100 ML. of methyl alcohol. Solidwas present throughout the stirring period (2 hours), and took on asilky-like appearance. The fluffy-white solid was collected, washed withether and air-dried to give 14.7 g (correspondingto a yield of 8.8percent of theory) of crude product. This material did not melt up to210 but shrank and became progressively darker. The analyicalsample wasrecrystallized from hot methanol. The crude product (3.0 g) wasdissolved in 60 cc hot methanol and filtered. After standing overnight,the solid was collected, washed and dried to give 1.4 g (47 percent) ofdry material. This material was identified asN-lauroyl-N-carboxamidinemethyl-glycinonitrile hydrochloride byelemental analysis and by its infrared ii g in cr12 m-o N ClIz-CNlI-IICI.

Nllz

. EXAMPLE lV (Preparation ofN-benzolyl-N-carboxamidinemethylglycinonitrile hydrobroniide) In a literflask fitted with a stirrer, thermometer, and

drying tube was placed 300 ml. of anhydrous methanol and 2 g (0.04 mole)of sodium methoxide. N benzolyliminodiacetonitrile (79.6 g; 0.4 mole)was added and dissolved after stirring 15 minutes at room temperature.After stirring 7 hours and standing over night, a yellowish solid waspresent. This was collected by centrifugation and air-dried. More solidwas recovered by evaporation of the'mother liquor. A total of 69.0 g(corresponding to a yield of 75 percent of theory) of crude imidoetherwas obtained. This material was a yellow-tan solid which showed nodefinite melting point; the material darkened on heating and beagan todecompose at approximately 190. Titration of the crude product gave anequivalent weight of 253. This material was identified as N-benzoyl-N-(2-methyl acetimidate)-glycinonitrile by infrared and the determinationof its equivalent weight.

Ammonium bromide (10 g; 0.1 1 mole) was added to a slurry of 23.1 g ofthe crude imidoether in 250ml. anhydrous methanol. The slurry wasstirred magnetically for 3 hours and allowed to stand overnight. Thepale yellow solid was collected by centrifugation, washed with coldmethanol and dried in a desiccator. It was identified asN-benzoyl-N-carboxamidinemethylglycinonitrile hydrobromide by elementalanalysis and by its infrared spectrum. The elemental analysis wasCalculated for C H N OBr: %C 44.46 %l-l 4.41

%N 18.85 Found 43.94 4.49 18.58 corresponding to CmcN EXAMPLE v(Preparation of N-cyanomethyl nitrilodiacetamide dihydrobromide) fNitrilotriacetonitrile (26.8 g; 0.2mole) and sodium "methoxide (0.02mole) was stirred in 225 ml. methanol for 7 hours and allowed to standovernight. Addition ,of ammonium bromide (59 g'; 0.6 mole)-wi thstirring icaused precipitation of a light tan solid. The reactionmixture was stirre'd an additional 2.5 hours, and the solid was thencollected and dried, to give 59.2 g (89.5

percent) of N-cyanomethyl-nitrilodiacetamidine dihydrobromide. Theproduct was identified by elemental analysis and 'by infrared spectrum.

. Since the product was shown to have the diamidine. structure, I

the intermediate imidocther was similarly identified as thediimidocthcr,

amidine salt having the formula lIX wherein'X is an ion selected fromthe group consisting of chloride and bromide.

2. An amidine salt having the formula